Infrared astronomy
Encyclopedia
Infrared astronomy is the branch of astronomy
and astrophysics
that studies astronomical object
s visible in infrared
(IR) radiation. The wavelength
of infrared light ranges from 0.75 to 300 micrometers. Infrared falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter
waves.
Infrared astronomy began in the 1830s, a few decades after the discovery of infrared light by William Herschel
in 1800. Early progress was limited, and it was not until the early 20th century that conclusive detections of astronomical objects other than the Sun
and Moon
were detected in infrared light. After a number of discoveries were made in the 1950s and 1960s in radio astronomy
, astronomer
s realized the information available outside of the visible wavelength range, and modern infrared astronomy was established.
Infrared and optical astronomy are often practiced using the same telescope
s, as the same mirror
s or lens
es are usually effective over a wavelength range that includes both visible and infrared light. Both fields also use solid state
detectors, though the specific type of solid state detectors used are different. Infrared light is absorb
ed at many wavelengths by water vapor in the Earth's atmosphere
, so most infrared telescopes are at high elevations in dry places, above as much of the atmosphere as possible. There are also infrared observatories in space, including the Spitzer Space Telescope
and the Herschel Space Observatory
.
. He noticed that the temperature increase induced by sunlight was highest outside the visible spectrum, just beyond the red color. That the temperature increase was highest at infrared wavelengths was due to the spectral index
of the prism rather than properties of the Sun, but the fact that there was any temperature increase at all prompted Herschel to deduce that there was invisible radiation from the Sun. He dubbed this radiation "calorific rays", and went on to show that it could be reflected, transmitted, and absorbed just like visible light.
Efforts were made starting in the 1830s and continuing through the 19th century to detect infrared radiation from other astronomical sources. Radiation from the Moon was first detected in 1873 by William Parsons, 3rd Earl of Rosse
. Ernest Fox Nichols
used a modified Crookes radiometer
in an attempt to detect infrared radiation from Arcturus and Vega
, but Nichols deemed the results inconclusive. Even so, the ratio of flux he reported for the two star
s is consistent with the modern value, so George Rieke gives Nichols credit for the first detection of a star other than our own in the infrared.
The field of infrared astronomy continued to develop slowly in the early 20th century, as Seth Barnes Nicholson
and Edison Pettit
developed thermopile
detectors capable of accurate infrared photometry
and sensitive to a few hundreds of stars. The field was mostly neglected by traditional astronomers though until the 1960s, with most scientists who practiced infrared astronomy having actually been trained physicist
s. The success of radio astronomy during the 1950s and 1960s, combined with the improvement of infrared detector technology, prompted more astronomers to take notice, and infrared astronomy became well established as a subfield of astronomy.
s, such as those at Keck Observatory, operate effectively in the near infrared as well as at visible wavelengths. The far-infrared extends to submillimeter wavelengths, which are observed by telescopes such as the James Clerk Maxwell Telescope
at Mauna Kea Observatory
.
Like all other forms of electromagnetic radiation
, infrared is utilized by astronomers to study the universe
. Infrared telescopes, which includes most major optical telescopes as well as a few dedicated infrared telescopes, need to be chilled with liquid nitrogen
and shielded from warm objects. The reason for this is that objects with temperatures of a few hundred Kelvin
emit most of their thermal
energy at infrared wavelengths. If infrared detectors were not kept cooled, the radiation from the detector itself would contribute noise that would dwarf the radiation from any celestial source. This is particularly important in the mid-infrared and far-infrared regions of the spectrum.
To achieve higher angular resolution
, some infrared telescopes are combined to form astronomical interferometer
s. The effective resolution of an interferometer is set by the distance between the telescopes, rather than the size of the individual telescopes. When used together with adaptive optics
, infrared interferometers, such as two 10 meter telescopes at Keck Observatory or the four 8.2 meter telescopes that make up the Very Large Telescope
Interferometer, can achieve high angular resolution.
The principal limitation on infrared sensitivity from ground-based telescopes is the Earth's atmosphere. Water vapor absorbs a significant amount of infrared radiation, and the atmosphere itself emits at infrared wavelengths. For this reason, most infrared telescopes are built in very dry places at high altitude, so that they are above most of the water vapor in the atmosphere. Suitable locations on Earth
include Mauna Kea Observatory at 4205 meters above sea level, the ALMA site
at 5000 m in Chile
and regions of high altitude ice-desert such as Dome C
in Antarctic
. Even at high altitudes, the transparency of the Earth's atmosphere is limited except in infrared windows, or wavelengths where the Earth's atmosphere is transparent. The main infrared windows are listed below:
As is the case for visible light telescopes, space is the ideal place for infrared telescopes. In space, images from infrared telescopes can achieve higher resolution, as they do not suffer from blurring
caused by the Earth's atmosphere, and are also free from absorption caused by the Earth's atmosphere. Current infrared telescopes in space include the Herschel Space Observatory, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer
. Since putting telescopes in orbit is expensive, there are also airborne observatories, such as the Stratospheric Observatory for Infrared Astronomy
and the Kuiper Airborne Observatory
. These observatories place telescopes above most, but not all, of the atmosphere, which means there is absorption of infrared light from space by water vapor in the atmosphere.
detectors, low temperature bolometer
arrays or photon-counting Superconducting Tunnel Junction arrays.
Special requirements for infrared astronomy include: very low dark currents to allow long integration times, associated low noise readout circuits and sometimes very high pixel
counts.
Low temperature is often achieved by a coolant, which can run out. Space missions have either ended or shifted to "warm" observations when the coolant supply used up. For example, WISE
ran out of coolant in October 2010, about ten months after being launched. (See also NICMOS, Spitzer Space Telescope)
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
and astrophysics
Astrophysics
Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...
that studies astronomical object
Astronomical object
Astronomical objects or celestial objects are naturally occurring physical entities, associations or structures that current science has demonstrated to exist in the observable universe. The term astronomical object is sometimes used interchangeably with astronomical body...
s visible in infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
(IR) radiation. The wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
of infrared light ranges from 0.75 to 300 micrometers. Infrared falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter
Terahertz radiation
In physics, terahertz radiation refers to electromagnetic waves propagating at frequencies in the terahertz range. It is synonymously termed submillimeter radiation, terahertz waves, terahertz light, T-rays, T-waves, T-light, T-lux, THz...
waves.
Infrared astronomy began in the 1830s, a few decades after the discovery of infrared light by William Herschel
William Herschel
Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...
in 1800. Early progress was limited, and it was not until the early 20th century that conclusive detections of astronomical objects other than the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
and Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
were detected in infrared light. After a number of discoveries were made in the 1950s and 1960s in radio astronomy
Radio astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The initial detection of radio waves from an astronomical object was made in the 1930s, when Karl Jansky observed radiation coming from the Milky Way. Subsequent observations have identified a number of...
, astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
s realized the information available outside of the visible wavelength range, and modern infrared astronomy was established.
Infrared and optical astronomy are often practiced using the same telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
s, as the same mirror
Mirror
A mirror is an object that reflects light or sound in a way that preserves much of its original quality prior to its contact with the mirror. Some mirrors also filter out some wavelengths, while preserving other wavelengths in the reflection...
s or lens
Lens (optics)
A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element...
es are usually effective over a wavelength range that includes both visible and infrared light. Both fields also use solid state
Solid state (electronics)
Solid-state electronics are those circuits or devices built entirely from solid materials and in which the electrons, or other charge carriers, are confined entirely within the solid material...
detectors, though the specific type of solid state detectors used are different. Infrared light is absorb
Absorption (electromagnetic radiation)
In physics, absorption of electromagnetic radiation is the way by which the energy of a photon is taken up by matter, typically the electrons of an atom. Thus, the electromagnetic energy is transformed to other forms of energy for example, to heat. The absorption of light during wave propagation is...
ed at many wavelengths by water vapor in the Earth's atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
, so most infrared telescopes are at high elevations in dry places, above as much of the atmosphere as possible. There are also infrared observatories in space, including the Spitzer Space Telescope
Spitzer Space Telescope
The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
and the Herschel Space Observatory
Herschel Space Observatory
The Herschel Space Observatory is a European Space Agency space observatory sensitive to the far infrared and submillimetre wavebands. It is the largest space telescope ever launched, carrying a single mirror of in diameter....
.
History
The discovery of infrared radiation is attributed to William Herschel, who performed an experiment where he placed a thermometer in sunlight of different colors after it passed through a prismPrism (optics)
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use...
. He noticed that the temperature increase induced by sunlight was highest outside the visible spectrum, just beyond the red color. That the temperature increase was highest at infrared wavelengths was due to the spectral index
Spectral index
In astronomy, the spectral index of a source is a measure of the dependence of radiative flux density on frequency. Given frequency \nu and radiative flux S, the spectral index \alpha is given implicitly byS\propto\nu^\alpha....
of the prism rather than properties of the Sun, but the fact that there was any temperature increase at all prompted Herschel to deduce that there was invisible radiation from the Sun. He dubbed this radiation "calorific rays", and went on to show that it could be reflected, transmitted, and absorbed just like visible light.
Efforts were made starting in the 1830s and continuing through the 19th century to detect infrared radiation from other astronomical sources. Radiation from the Moon was first detected in 1873 by William Parsons, 3rd Earl of Rosse
William Parsons, 3rd Earl of Rosse
William Parsons, 3rd Earl of Rosse, Knight of the Order of St Patrick was an Irish astronomer who had several telescopes built. His 72-inch telescope "Leviathan", built 1845, was the world's largest telescope until the early 20th century.-Life:He was born in Yorkshire, England, in the city of...
. Ernest Fox Nichols
Ernest Fox Nichols
Ernest Fox Nichols was a U.S. educator and physicist. He was born in Leavenworth County, Kansas, and received his undergraduate degree from Kansas State University in 1888. After working for a year in the Chemistry Department at Kansas State, he matriculated to graduate school at Cornell...
used a modified Crookes radiometer
Crookes radiometer
The Crookes radiometer, also known as the light mill, consists of an airtight glass bulb, containing a partial vacuum. Inside are a set of vanes which are mounted on a spindle. The vanes rotate when exposed to light, with faster rotation for more intense light, providing a quantitative measurement...
in an attempt to detect infrared radiation from Arcturus and Vega
Vega
Vega is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second brightest star in the northern celestial hemisphere, after Arcturus...
, but Nichols deemed the results inconclusive. Even so, the ratio of flux he reported for the two star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s is consistent with the modern value, so George Rieke gives Nichols credit for the first detection of a star other than our own in the infrared.
The field of infrared astronomy continued to develop slowly in the early 20th century, as Seth Barnes Nicholson
Seth Barnes Nicholson
Seth Barnes Nicholson was an American astronomer.Nicholson was born in Springfield, Illinois and was raised in rural Illinois...
and Edison Pettit
Edison Pettit
Edison Pettit was an American astronomer.He was born in Peru, Nebraska. He taught astronomy at Washburn College in Topeka, Kansas from 1914 to 1918. He married Hannah Steele, who was an assistant at Yerkes Observatory, and received his Ph.D...
developed thermopile
Thermopile
A thermopile is an electronic device that converts thermal energy into electrical energy. It is composed of several thermocouples connected usually in series or, less commonly, in parallel....
detectors capable of accurate infrared photometry
Photometry (astronomy)
Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation...
and sensitive to a few hundreds of stars. The field was mostly neglected by traditional astronomers though until the 1960s, with most scientists who practiced infrared astronomy having actually been trained physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
s. The success of radio astronomy during the 1950s and 1960s, combined with the improvement of infrared detector technology, prompted more astronomers to take notice, and infrared astronomy became well established as a subfield of astronomy.
Modern infrared astronomy
Infrared radiation with wavelengths just longer than visible light, known as near-infrared, behaves in a very similar way to visible light, and can be detected using similar solid state devices. For this reason, the near infrared region of the spectrum is commonly incorporated as part of the "optical" spectrum, along with the near ultraviolet. Many optical telescopeOptical telescope
An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for making a photograph, or collecting data through electronic image sensors....
s, such as those at Keck Observatory, operate effectively in the near infrared as well as at visible wavelengths. The far-infrared extends to submillimeter wavelengths, which are observed by telescopes such as the James Clerk Maxwell Telescope
James Clerk Maxwell Telescope
The James Clerk Maxwell Telescope is a submillimetre-wavelength telescope at Mauna Kea Observatory in Hawaii. Its primary mirror is 15 metres across: it is the largest astronomical telescope that operates in submillimetre wavelengths of the electromagnetic spectrum...
at Mauna Kea Observatory
Mauna Kea Observatory
The Observatories at Mauna Kea, , are an independent collection of astronomical research facilities located on the summit of Mauna Kea on the Big Island of Hawai'i, USA. The facilities are located in a special land use zone known as the "Astronomy Precinct," which is located in the Mauna Kea...
.
Like all other forms of electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
, infrared is utilized by astronomers to study the universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
. Infrared telescopes, which includes most major optical telescopes as well as a few dedicated infrared telescopes, need to be chilled with liquid nitrogen
Liquid nitrogen
Liquid nitrogen is nitrogen in a liquid state at a very low temperature. It is produced industrially by fractional distillation of liquid air. Liquid nitrogen is a colourless clear liquid with density of 0.807 g/mL at its boiling point and a dielectric constant of 1.4...
and shielded from warm objects. The reason for this is that objects with temperatures of a few hundred Kelvin
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
emit most of their thermal
Thermal
A thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...
energy at infrared wavelengths. If infrared detectors were not kept cooled, the radiation from the detector itself would contribute noise that would dwarf the radiation from any celestial source. This is particularly important in the mid-infrared and far-infrared regions of the spectrum.
To achieve higher angular resolution
Angular resolution
Angular resolution, or spatial resolution, describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object...
, some infrared telescopes are combined to form astronomical interferometer
Astronomical interferometer
An astronomical interferometer is an array of telescopes or mirror segments acting together to probe structures with higher resolution by means of interferometry....
s. The effective resolution of an interferometer is set by the distance between the telescopes, rather than the size of the individual telescopes. When used together with adaptive optics
Adaptive optics
Adaptive optics is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems to reduce the...
, infrared interferometers, such as two 10 meter telescopes at Keck Observatory or the four 8.2 meter telescopes that make up the Very Large Telescope
Very Large Telescope
The Very Large Telescope is a telescope operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. The VLT consists of four individual telescopes, each with a primary mirror 8.2m across, which are generally used separately but can be used together to...
Interferometer, can achieve high angular resolution.
The principal limitation on infrared sensitivity from ground-based telescopes is the Earth's atmosphere. Water vapor absorbs a significant amount of infrared radiation, and the atmosphere itself emits at infrared wavelengths. For this reason, most infrared telescopes are built in very dry places at high altitude, so that they are above most of the water vapor in the atmosphere. Suitable locations on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
include Mauna Kea Observatory at 4205 meters above sea level, the ALMA site
Atacama Large Millimeter Array
The Atacama Large Millimeter/sub-millimeter Array is an array of radio telescopes in the Atacama desert of northern Chile. Since a high and dry site is crucial to millimeter wavelength operations, the array is being constructed on the Chajnantor plateau at 5000 metres altitude...
at 5000 m in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
and regions of high altitude ice-desert such as Dome C
Dome C
Dome C, also known as Dome Circe or Dome Charlie, located at Antarctica at an altitude of 3,233 m or 10,607 ft above sea level, is one of several summits or "domes" of the Antarctic Ice Sheet...
in Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
. Even at high altitudes, the transparency of the Earth's atmosphere is limited except in infrared windows, or wavelengths where the Earth's atmosphere is transparent. The main infrared windows are listed below:
| Wavelength range (micrometre Micrometre A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm... s) | Astronomical bands | Telescopes |
|---|---|---|
| 0.65 to 1.0 | R and I bands | All major optical telescopes |
| 1.1 to 1.4 | J band | Most major optical telescopes and most dedicated infrared telescopes |
| 1.5 to 1.8 | H band | Most major optical telescopes and most dedicated infrared telescopes |
| 2.0 to 2.4 | K band | Most major optical telescopes and most dedicated infrared telescopes |
| 3.0 to 4.0 | L band | Most dedicated infrared telescopes and some optical telescopes |
| 4.6 to 5.0 | M band | Most dedicated infrared telescopes and some optical telescopes |
| 7.5 to 14.5 | N band | Most dedicated infrared telescopes and some optical telescopes |
| 17 to 25 | Q band | Some dedicated infrared telescopes and some optical telescopes |
| 28 to 40 | Z band | Some dedicated infrared telescopes and some optical telescopes |
| 330 to 370 | Some dedicated infrared telescopes and some optical telescopes | |
| 450 | submillimeter | Submillimeter telescopes |
As is the case for visible light telescopes, space is the ideal place for infrared telescopes. In space, images from infrared telescopes can achieve higher resolution, as they do not suffer from blurring
Scintillation (astronomy)
Scintillation or twinkling are generic terms for rapid variations in apparent brightness or color of a distant luminous object viewed through a medium, most commonly the atmosphere ....
caused by the Earth's atmosphere, and are also free from absorption caused by the Earth's atmosphere. Current infrared telescopes in space include the Herschel Space Observatory, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer is a NASA infrared-wavelength astronomical space telescope launched on December 14, 2009, and decommissioned/hibernated on February 17, 2011 when its transmitter was turned off...
. Since putting telescopes in orbit is expensive, there are also airborne observatories, such as the Stratospheric Observatory for Infrared Astronomy
Stratospheric Observatory for Infrared Astronomy
The Stratospheric Observatory for Infrared Astronomy is a joint project of NASA and the German Aerospace Center to construct and maintain an airborne observatory. NASA awarded the contract for the development of the aircraft, operation of the observatory and management of the American part of the...
and the Kuiper Airborne Observatory
Kuiper Airborne Observatory
The Gerard P. Kuiper Airborne Observatory was a national facility operated by NASA to support research in infrared astronomy. The observation platform was a highly modified C-141A jet transport aircraft with a range of 6,000 nautical miles , capable of conducting research operations up to 48,000...
. These observatories place telescopes above most, but not all, of the atmosphere, which means there is absorption of infrared light from space by water vapor in the atmosphere.
Infrared technology
One of the most common infrared detector arrays used at research telescopes is HgCdTe arrays. These operate well between 0.6 and 5 micrometre wavelengths. For longer wavelength observations or higher sensitivity other detectors may be used, including other narrow gap semiconductorNarrow gap semiconductor
Narrow gap semiconductors are semiconducting materials with a band gap that is comparatively small compared to silicon. They are used as infrared detectors or thermoelectrics.-List of Narrow gap semiconductors:*HgCdTe*PbSe*PbS*PbTe*InAs*InSb*Cd3As2...
detectors, low temperature bolometer
Bolometer
A bolometer is a device for measuring the power of incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley...
arrays or photon-counting Superconducting Tunnel Junction arrays.
Special requirements for infrared astronomy include: very low dark currents to allow long integration times, associated low noise readout circuits and sometimes very high pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
counts.
Low temperature is often achieved by a coolant, which can run out. Space missions have either ended or shifted to "warm" observations when the coolant supply used up. For example, WISE
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer is a NASA infrared-wavelength astronomical space telescope launched on December 14, 2009, and decommissioned/hibernated on February 17, 2011 when its transmitter was turned off...
ran out of coolant in October 2010, about ten months after being launched. (See also NICMOS, Spitzer Space Telescope)